Strain Energy Density Prediction of Mixed-Mode Crack Propagation in Functionally Graded Materials

Nabil Benamara,Miloud Aminallah,Abdelkader Boulenouar

doi:10.3311/ppme.9682

Abstract

The objective of this work is to present a numerical modeling of crack propagation path in functionally graded materials (FGMs) under mixed-mode loadings. The minimum strain energy density criterion (MSED) and the displacement extrapolation technique (DET) are investigated in the context of fracture and crack growth in FGMs. Using the Ansys Parametric Design Language (APDL), the direction angle is evaluated as a function of stress intensity factors (SIFs) at each increment of propagation and the variation continues of the material properties are incorporated by specifying the material parameters at the centroid of each finite element (FE). In this paper, several applications are investigated to check for the robustness of the numerical techniques. The defaults effect (inclusions and cavities) on the crack propagation path in FGMs are examined.

Highlights

Graded Materials (FGMs) are inhomogeneous materials which are widely used in technological application
Using the Ansys Parametric Design Language (APDL), the direction angle is evaluated as a function of stress intensity factors (SIFs) at each increment of propagation and the variation continues of the material properties are incorporated by specifying the material parameters at the centroid of each finite element (FE)
Tilbrook et al [5] investigated the effects of gradient profile and crack geometry on crack-tip stresses and crack propagation path in functionally graded materials (FGMs)

Summary

Introduction

Graded Materials (FGMs) are inhomogeneous materials which are widely used in technological application In recent years, those materials have been especially studied its mechanical behaviors using different approaches. For the fracture of the FGMs, many studies have considered various crack problems in non-homogeneous materials: Using finite element method (FEM) analysis, Kim and Paulino [1] evaluated the mixed-mode fracture parameters in FGMs with three techniques: Jk*-integral method, the displacement correlation technique (DCT) and the modified crack-closure integral method (MCC). The displacement correlation technique (DCT) and the modified crack closure (MCC) are used to evaluate SIFs in orthotropic FGMs. Chang-chun et al [8] used the coupled method to calculate the Rice’s J-integral for dynamic fracture in single edge cracked FGM panel. Sladek et al [12] proposed the meshless method based on the local Petrov-Galerkin

Objectives

Conclusion